Surgical instrument storage and sterilization systems are known. These systems, known as surgical instrument trays or surgical instrument kits, typically consist of metal or plastic trays that hold a variety of general purpose and/or procedure specific surgical instruments such as forceps, scissors, clamps, retractors, scalpels, etc. These trays are brought into the operating room (OR) when preparing for surgery, and also are used as a means to organize, transport and store surgical instruments in a medical facility. For the purposes of this disclosure and claims, the terms “surgical instrument kit”, “surgical instrument tray”, “surgical kit”, “surgical tray”, “kit” and “tray” will be used interchangeably to refer to devices used in the medical industry to hold, house and transport multiple surgical instruments.
A primary function provided by surgical trays, in addition to storage, is to facilitate group sterilization. Sterilization is of paramount importance in a surgical setting such as a hospital to prevent potentially deadly infections to patients undergoing surgery. Prior to every surgical procedure, all surgical instruments and trays must be sterilized. Also, following each surgical procedure, all instruments on a given tray, if not wrapped separately, whether soiled or not, must be re-sterilized before subsequent usage. In order to increase the speed and efficiency of sterilization, entire surgical trays containing several instruments often are placed in a sterilization chamber at once. The sterilization chamber may provide any combination of heat, pressure, and/or fluid or vaporous sterilant to the trays and all the instruments contained therein. Sterilization techniques are well known. Thus, a detailed discussion of them has been intentionally omitted.
Because of the need to perform sterilization and the general need to maintain surgical instruments kits in good working order, they are often transported in and out of medical facilities through a distribution center for processing. For example, a group of surgical instrument kits may be picked up from a hospital at one time. In order to easily and efficiently transport the kits, several kits are placed in a single shipping tote. The shipping tote is a large bin, usually made of plastic or other durable lightweight material and able to securely hold two or more instrument kits inside. A worker then may load the shipping totes into a truck thereby reducing the number of manual operations that must be performed. Before transporting each shipping tote, a bar coded shipping label is prepared that identifies certain information such as the point of origin, the destination, and possibly the contents of the tote, i.e., the identification number of each surgical instrument tray contained in the tote. The bar coded label allows the tote to be easily and efficiently tracked and entered into inventory at the receiving facility.
While bar code labels work well for shipping labels, they are not well suited as a means for identifying surgical instrument trays themselves. Typically, in order to identify instrument trays, a worker will have to physically inspect each instrument tray for an identification number or even identify each tray from memory in order to accurately record intake of the tray during processing. As noted above, bar code labels are not practical in this application because they can not hold up to the rigors of sterilization. Moreover, they require line of sight in order to be read, further increasing processing and handling time by the person attempting to identify them. A promising memory device-based product identification technology that ameliorates some of these noted deficiencies of bar coded labels is that of radio frequency identification (RFID) technology. RFID systems use an RF field generator and a plurality of RFID tags attached to goods and products to store and retrieve information about the goods and products. RFID tags are miniature electronic circuits that store identification information about the products they are attached to. An RFID tag typically includes a memory for storing data, an antenna, an RF transmitter, and/or an RF receiver to transmit data, and logic for controlling the various components of the memory device. The basic structure and operation of RFID tags can be found in, for example, U.S. Pat. Nos. 4,075,632, 4,360,801, 4,390,880, 4,739,328 and 5,030,807, the disclosures of which are hereby incorporated by reference in their entirety.
RFID tags generally are formed on a substrate and can include, for example, analog RF circuits and digital logic and memory circuits. The RFID tags also can include a number of discrete components, such as capacitors, transistors, and diodes. The RF transmission of data can be accomplished with modulated back scatter as well as modulation of an active RF transmitter. These RFID tags typically come in one of two types: active or passive. Active tags are characterized in that they have their own power source, such as a battery. When they enter an RF field they are turned on and then emit a signal containing their stored information. Passive tags do not contain a discrete power source. Rather, they become inductively charged when they enter an RF field. Once the RF field has activated the passive circuit, they emit a signal containing their stored information. Passive RFID tags usually include an analog circuit that detects and decodes the interrogating RF signal and that provides power from the RF field to a digital circuit in the tag. The digital circuit generally executes all of the data functions of the RFID tag, such as retrieving stored data from memory and causing the analog circuit to modulate to the RF signal to transmit the retrieved data. In addition to retrieving and transmitting data previously stored in the memory, both passive and active dynamic RFID tags can permit new or additional information to be stored in the RFID tag's memory, or can permit the RFID tag to manipulate data or perform some additional functions. By attaching or integrating an RFID transponder tag in each surgical instrument tray, the tray can be identified wirelessly without requiring precise manual manipulation because RF waves can penetrate surfaces impervious to light. Thus, they do not require line of sight in order to be read and can be encapsulated into ruggedized containers. Another advantage is that a group of tags placed within the influence of an RFID reader can read nearly simultaneously. Yet another advantage of RFID tags is that with dynamic tags, the stored information can be updated using a suitable reader/writer device, allowing them to serve as transactional records.
The description herein of various advantages and disadvantages associated with known apparatus, methods, and materials is not intended to limit the scope of the invention to their exclusion. Indeed, various embodiments of the invention may include one or more of the known apparatus, methods, and materials without suffering from their disadvantages.